Purge flow vale problem
 

I have a '96 Mustang that is getting a P1443 code. I have done a lot of the stuff on the forum to try and troubleshoot the problem. I narrowed the problem down to the Purge flow valve. I have replaced the valve twice with a brand new valve. It is getting around 12 - 13 volts to the electrical connection on the Purge Flow Valve, but the valve is not opening. I checked the vacuum on the inlet side and there is a very strong vacuum there, but no vacuum on the outlet even though voltage is going to the valve. Is there anything else that could be causing this problem? Thank you,

Craig